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PHYSIO CH. 14 REVIEW QS

Terms in this set (32)

Dr. Danielle Reed recognized that her sense of taste was unique compared with other people she knew. now, she studies the genetic differenced between people and their sensitivities to taste stimuli. in the video, there is a brief image of a person sticking out there tongue, which has been covered with a colored dye. this is how dr. reed is able to visualize and count papillae on the surface of the tongue. people fall into 2 large groups known as "tasters" and "nontasters" on the basis of the density of papillae on their tongue, which also indicates the number of taste buds. non-tasters can taste food, but they are not as sensitive to certain tastes, such as bitterness. dr. reed discovered that she is a non-taster, which explains why perceived bitterness differently than other people. are you sensitive to tastes? can you see any similarities among the members of your family?
answers will vary but here's an example: i can eat most anything (except mushrooms), so i dont think that i am that sensitive to tastes. my whole family like eating a variety of foods so it seems that we all have the same level of sensitivity.
the basilar membrane is the thin membrane that extends from the central core of the cochlea to the edge. what is anchored to this membrane so that they can be activated by movement of the fluids within the cochlea?
the hair cells are located in the organ of corti, which is located on the basilar membrane. the stereocilia of those cells would normally be attached to the tectorial membrane (though they are detached in the micrograph because of processing o the tissue)
specific locations along the length of the duct encode specific frequencies, or pitches. the brain interprets the meaning of the sounds we hear as music, speech, noise, etc. which ear structures are responsible for the amplification and transfer of sound from the external ear to the inner ear?
the small bones in the middle ear, the ossicles, amplify and transfer sound between the tympanic membrane of the external ear and the oval window of the inner ear.
specific wavelengths of sound cause specific regions of the basilar membrane to vibrate, much like the keys of a piano produce sound at different frequencies. based on the animation, where do frequencies--from high to low pitches--cause activity in the hair cells within the cochlear duct?
high frequencies activate hair cells toward the base of the cochlea, and low frequencies activate hair cells toward the apex of the cochlea.
watch this video to learn more about a transverse section through the brain that depicts the visual pathway from the eye to the occipital cortex. the first half of the pathway is the projection from the RGCs through the optic nerve to the lateral geniculate nucleus in the thalamus on either side. this first fiber in the pathway synapses on a thalamic cell that then projects to the visual cortex in the occipital lobe where "seeing", or visual perception takes place. this video gives an abbreviated overview of the visual system by concentrating on the pathway from the eyes to the occipital lobe. the video states that "specialized cells in the retina called ganglion cells convert the light rays into electrical signals." what aspect of retinal processing is simplified by that statement? explain.
photoreceptors covert light energy, or photons, into an electrochemical signal. the retina contains bipolar cells and the RGCs that finally convert it into action potentials that are sent from the retina to the CNS. it is important to recognize when popular media and online sources oversimplify complex physiological processes so that misunderstandings are not generated. this video was created by a medical device manufacturer who might be trying to highlight other aspects of the visual system than retinal processing. the statement they make is not incorrect, it just bundles together several steps, which makes it sound like RGCs are transducers, rather than photoreceptors.
similar to how retinal disparity offers 3D moviegoers a way to extract 3D information from the 2-dimensional visual field projected onto the retina, the brain can extract info about movement in space by comparing what the two eyes see. if movement of a visual stimulus is leftward in one eye and rightward in the opposite eye, the brain interprets this as movement toward (or away from) the face along the midline. if both eyes see an object moving in the same direction, but at different rates, what would that mean for spatial movement?
movement past one side of the head will result in movement in the same direction on both retinae, but it will be slower in the eye on the side nearer to the object
the inability to recognize people by their faces is a troublesome problem. it can be caused by trauma, or it may be inborn. watch this video to learn more about a person who lost the ability to recognize faces as the result of an injury. she cannot recognize the faces of close family members or herself. what other info can a person suffering from prosopagnosia use to figure out whom they are seeing?
even if a person cannot recognize a person's face, other cues such as clothing, hairstyle, or a particular feature such as a prominent nose or facial hair, can help make an identification.
watch this video to learn more about the descending motor pathway for the somatic nervous system. the autonomic connections are mentioned, which are covered in another chapter. from this brief video, only some of the descending motor pathway of the somatic nervous system is described. which division of the pathway is described and which division is left out?
IDK
what regions of the nervous system are likely to be the focus of haloperidol side effects?
the movement disorders were similar to those seen in movement disorders of the extrapyramidal system, which would mean the basal nuclei are the most likely source of haloperidol side effects. in fact, haloperidol affects dopamine activity, which is a prominent part of the chemistry of the basal nuclei.
when the right cornea senses a tactile stimulus, what happens to the left eye? explain.
the left eye also blinks. the sensory input from one eye activates the motor response of both eyes so that they both blink.
newborns have a set of reflexes that are expected to have been crucial to survival before the modern age. these reflexes disappear as the baby grows, as some of them may be unnecessary as they age. the video demonstrates a reflex called the babinski reflex, in which the foot flexes dorsally and the toes splay out when the sole of the foot is lightly scratched. this is normal for newborns, but it is a sign of myelination of the spinal tract in adults. why would this reflex be a problem for an adult?
while walking, the sole of the foot may be scraped or scratched by many things. if the foot still reacted as in the babinski reflex, an adult might lose their balance while walking
what type of receptor cell is responsible for transducing pain stimuli?
nocireceptor
which of these cranial nerves is part of the gustatory system?
facial
which submodality of taste is sensitive to the pH of saliva?
sour
axons from which neuron in the retina make up the optic nerve?
retinal ganglion cells
what type of receptor cell is involved in the sensations of sound and balance?
mechanoreceptor
which of these sensory modalities does NOT pass through the ventral posterior thalamus?
a. gustatory
b. proprioception
c. audition
d. nociception
audition
which nucleus in the medulla is connected to the inferior colliculus?
cochlear nucleus
visual stimuli in the upper left visual field will be processed in what region of the primary visual cortex?
inferior right
which location on the body has the largest region of somatosensory cortex representing it, according to the sensory homonculus?
lips
which of the following is a direct target of the vestibular ganglion?
a. superior colliculus
b. cerebellum
c. thalamus
d. optic chiasm
cerebellum
which region of the frontal lobe is responsible for initiating movement by directly connecting to cranial and spinal motor neurons?
primary motor cortex
which extrapyramidal tract incorporates equilibrium sensations with motor commands to aid in posture and movement?
vestibulospinal tract
which region of gray matter in the spinal cord contains motor neurons that innervate skeletal muscles?
ventral horn
what type of reflex can protect the foot when a painful stimulus is sensed?
withdrawal reflex
what is the name for the topographical representation of the sensory input to the somatosensory cortex?
homonculus
the sweetener known as stevia can replace glucose in food. what does the molecular similarity of stevia to glucose mean for the gustatory sense?
the stevia molecule is similar to glucose such that it will bind to the glucose receptor in sweet-sensitive taste buds. however, it is not a substrate for the ATP-generating metabolism within cells.
why does the blind spot from the optic disc in either eye not result in a blind spot in the visual field?
the visual field for each eye is projected onto the retina as light is focused by the lens. the visual info from the right visual field falls on the left side of the retina and vice versa. the optic disc in the right eye is on the medial side of the fovea, which would be the left side of the retina. however, the optic disc in the left eye would be on the right side of the fovea, so the right visual field falls on the side of the retina in the left field where there is no blind spot.
following a motorcycle accident, the victim loses the ability to move the right leg but has normal control over the left one, suggesting a hemisection somewhere in the thoracic region of the spinal cord. what sensory deficits would be expected in terms of touch vs. pain? explain.
the right leg would feel painful stimuli, but not touch, because the spinothalamic tract decussates at the level of entry, which would be below the injury, whereas the dorsal column system does not decussate until reaching the brain stem, which would be above the injury and thus those fibers would be damaged.
a pituitary tumor can cause perceptual losses in the lateral visual field. the pituitary gland is located directly inferior to the hypothalamus. why would this happen?
the optic chiasm is the junction wherein each half of the brain receives visual signals from the visual fields of both eyes. as the tumor in the hypothalamus grow in size, pituitary adenomas can put pressure on important structures in the body, such as the optic nerve. putting pressure on the optic nerve may cause blindness. the optic nerve could be impeded by the tumor.
the prefrontal lobotomy is a drastic--and largely out of practice--procedure used to disconnect that portion of the cerebral cortex from the rest of the frontal lobe and the diencephalon as a psychiatric therapy. why would this have been thought necessary for someone with a potentially uncontrollable behavior?
the prefrontal cortex is involved in decision-making functions that lead to motor responses through connections to the more posterior motor regions. these early aspects of behavior are often associated with a person's personality, so disrupting those connections will lead to severe changes in behavior.
if a reflex is a limited circuit within the somatic system, why do physical and neurological exams include them to test the health of an individual?
because test of reflexes are a reflection of the functionality of the nerves which can detect more serious problems in the body. the functionality or responsiveness of the reflex can be representative of the state of the more complex circuits that is why it is included in neurological tests
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